This invention relates to the field of consumer electronics systems, and more particularly, to apparatus, methods, and systems for transmitting wireless signals within such consumer electronics systems.
There has been long-standing concern regarding the undesirable jamming of infrared (IR) signals transmitted within consumer electronics systems. Such IR jamming occurs when two or more transmitting devices simultaneously transmit IR signals that cannot be resolved at a receiving device. A typical scenario in which IR jamming may occur involves consumer electronics systems, such as home theater systems, wherein primary and secondary IR signals are transmitted between the components of the consumer electronics system.
For example, FIG. 1 depicts a prior art consumer electronics system 10, which generally includes a remote control 12, a television 14, and an audio/video device 16, e.g., an audio receiver, video cassette recorder (VCR), etc. The remote control 12 can be used to perform a variety of operations within the consumer electronics system 10. The performance of such operations within the consumer electronics system 10 may require different transmission protocols to be used, since typically, the individual components of a consumer electronics system are fabricated by different manufacturers. These differences, however, are transparent to the remote control 12, which utilizes the television 14 to communicate with other devices, including the audio/video device 16. This arrangement, however, is susceptible to IR jamming problems.
Although a jamming problem typically does not arise when the operation is performed within the television 14, the same cannot be said when the operation is performed within the audio/video device 16, since the remote control 12 communicates with the audio/video device 16 through the television 14, creating the possibility that two signals may be transmitted to the audio/video device 16. Specifically, an operation can be performed in the audio/video device 16 by depressing a corresponding remote function key 18 on the remote control 12. In response, a primary IR signal SIR1 is transmitted to the television 14. The television 14 detects and interprets the primary IR signal SIR1, and then transmits a corresponding secondary IR signal SIR2 to the audio/video device 16, which, in the absence of IR interference, effects the performance of the operation in the audio/video device 16. If the audio/video device 16 is visible to the remote control 12, however, there is a chance that the audio/video device 16 will receive the primary IR signal SIR1 as IR interference simultaneous with the secondary IR signal SIR2. In this case, the primary IR signal SIR1 acts as a jamming signal, thereby creating a jamming problem.
This jamming problem usually occurs when the remote function key 18 (e.g., the function key that controls volume-up or volume-down) is continuously depressed, creating a high likelihood that the remote control 12 will still be transmitting the primary IR signal SIR1 during transmission of the secondary IR signal SIR2 from the television 14. In this case, the remote control 12 does not gain control of the audio/video device 16 until the remote function key 18 is released, i.e., when the audio/video device 16 no longer receives the interfering primary IR signal SIR1. Thus, this specific jamming problem creates the annoying situation where the user, anticipating that the continuous depression of the remote function key 18 will repeatedly perform the corresponding operation in the audio/video device 16, continuously depresses the remote function key 18 with no results. Only after the remote function key 18 is released is the corresponding operation performed, but only slightly. Thus, in order to repeatedly perform the operation within the audio/video device 16, the user is forced to repeatedly depress the remote function key 18, which may be an annoying task in itself.
This IR jamming phenomenon is illustrated in FIG. 2. Waveform 20 represents the continuous depression of the remote function key 18, remaining high as long as the corresponding remote function key 18 is depressed. Waveform 22 represents the primary IR signal SIR1, which is transmitted from the remote control 12 in response to the depression of corresponding the remote function key 18. As can be seen, the primary IR signal SIR1 is continuously transmitted in the form of a series of data blocks 28 for the duration that the corresponding remote function key 18 remains depressed. Waveform 24 represents the secondary IR signal SIR2, which is transmitted from the television 14 in response to the detection and interpretation of the primary IR signal SIR1. The secondary IR signal SIR2 is continuously transmitted in the form of a series of data blocks 30 for the duration that the primary IR signal SIR1 is received from the remote control 12. Waveform 26 represents the duration of the performance of the corresponding operation within the audio/video device 16, remaining low until the operation is performed. As can be seen, the operation is not performed until the transmission of the primary IR signal SIR1 terminates, signifying the release of the corresponding function key 18. At this point, the audio/video device 16 is receiving only the secondary IR signal SIR2, allowing the corresponding operation to be performed without significant IR interference. Such control is momentary, however, since the transmission of the secondary IR signal SIR2 ceases when the primary IR signal SIR1 is no longer detected.
Thus, there arises a need to prevent IR jamming in consumer electronics systems that utilize primary and secondary signals to effect the performance of an operation in response to a continuous remote function key press.
The present inventions comprise novel methods and systems for preventing such jamming. In accordance with a first aspect of the present inventions, signal jamming within a consumer electronics system is prevented by wirelessly transmitting a primary signal comprising first and second messages having a predetermined quiescent period therebetween. In the preferred embodiment, the first and second messages are identical and each comprises one or more data blocks. The present inventions, however, should not be limited to this implementation. The primary signal is received and interpreted, and a secondary signal is generated and wirelessly transmitted in response to the primary signal. In the preferred embodiment, the third message corresponds with the first message. For example, both the first message and third message comprise a command that the volume be turned up or down in a component of the consumer electronics system. The secondary signal includes a third message, the entirety of which is transmitted during the quiescent period. In this manner, no portion of the primary signal messages and no portion of the secondary messages is transmitted at the same time. The primary and secondary signals may be transmitted at any frequency, but preferably are transmitted at IR frequencies, as most consumer electronics devices wirelessly communicate with each other using IR frequencies.
In accordance with a second aspect of the present inventions, an interpreting device can be implemented in the consumer electronics system. The interpreting device includes a receiver for receiving the wirelessly transmitted primary signal. The interpreting device further includes processing circuitry for interpreting the first message and generating a third message in response thereto. This processing circuitry may be implemented as a microcomputer or microprocessor. The interpreting device further includes a transmitter for wirelessly transmitting the third message within the secondary signal in a manner such that the third message is transmitted during the quiescent period. In the case where the first and second messages are formatted in accordance with a first protocol, and the third. message is formatted in accordance with a second protocol different from the first protocol, the interpreting device may be advantageously used as the interface between the device that transmitted the primary signal and the device that is to receive the secondary signal.
In accordance with a third aspect of the present inventions, signal jamming is prevented within a consumer electronics system having a remote control, an interpreting device, and an audio/video device. In the preferred embodiment, the interpreting device is implemented as a television. The interpreting device, however, can be any device that can receive and interpret a first signal, and then generate and transmit a second signal in response to the first signal. The audio/video device can be any device that provides audio, video, or both to a user, e.g., an audio processor, CD player, VCR, etc. In the method, the signal jamming is prevented even if a remote function key on the remote control is continuously operated. In response to such remote function key operation, a plurality of primary messages is wirelessly transmitted from the remote control, where each of one or more quiescent periods are located between the adjacent messages of the plurality of primary messages. The plurality of primary messages may be formatted in data blocks and may be identical to each other. The present inventions, however, should not be limited to such an implementation. The primary messages are then received at the interpreting device and interpreted. In response to the interpretation of the primary messages, one or more secondary messages are generated and wirelessly transmitted from the interpreting device to the audio/video device entirely during the one or more quiescent periods. The one or more secondary messages are preferably based on the interpreted plurality of primary messages, but the present inventions should not be so limited. To ensure that interference between the primary and secondary messages does not occur, each quiescent period is at least equal to the sum of the period of silence needed for the interpreting device to detect one of the plurality of primary messages, the duration of one of the one or more secondary messages, and the period of silence needed for the audio/video device to detect one of the one or more secondary messages.